1. Field of the Invention
The present invention relates to a data storage apparatus, provided in an electronic IC card incorporating an IC chip having a nonvolatile memory and a control element for controlling the nonvolatile memory, which apparatus provided in an electronic IC card incorporating an IC chip having a nonvolatile memory and a control element for a predetermined type which are divisionally set in the memory, an example of the electronic apparatus being an IC card incorporating an IC chip having a nonvolatile memory and an example of the control element being a CPU.
2. Description of the Related Art
In recent years, a popular portable data storage medium has emerged including an IC card incorporating an IC chip having a nonvolatile data memory and a control element such as a CPU for controlling the nonvolatile memory.
In an IC card of this type, an incorporated data memory is divided into a plurality of areas, and data processed in a predetermined application are stored in the areas, respectively. A method of writing or reading binary data is typically used to access the data in these areas.
An IC card having the above-mentioned is described in Japanese Patent Application (KOKAI) Publication No. 4-40587 corresponding to U.S. patent application Ser. No. 07/710,025 now U.S. Pat. No. 5,365,045.
In this IC card, an area of a memory that is allocated to a user, known as "a user's area", is divided into a plurality of sub-areas. A prescribed initial code such as "FF" or "00 is written to each user's area, and used to confirm the reliability of the user's area by checking whether the prescribed code is correctly written or not. However, other data cannot be written into the user's area using the same method for both the initial code "FF" and the initial code "00". Rather, when the initial code is "FF", data must be written using AND logic, and when the initial code is "00", data must be written using OR logic.
Accordingly, when an IC card is processed in an IC card processing apparatus, the IC card memory must indicate the a prescribed initial logic condition, e.g., AND logic condition or the OR logic condition. If an IC card having a memory having a different logic condition, than that prescribed, is inserted into the IC card processing apparatus, this card cannot be processed therein. For example, when the prescribed writing method for a device is based on the AND logic and user's areas have a corresponding initial code of "FF", a card having an initial code of ".phi..phi." cannot be written to.
Moreover, for an IC card provided as a multi-purpose card suited for a plurality of user's systems to conventional system requires, an initial status inherent to each user's system to be stored in each user's area when the IC card is issued.
However, when different initial logic conditions are set in the memory areas provided for the plurality of user's system, it is necessary to change the logic condition of data to be written in the different user's area of the memory, thereby lowering the processing speed for issuing the IC card.